CONSOLIDATED STATEMENTS OF CASH FLOWS (Unaudited) - USD ($)	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
Operating activities:
Net income	$ 93,960,000	$ 83,510,000
Adjustments to reconcile net income to net cash provided by operating activities:
Net amortization/accretion of premium/discount on securities	4,309,000	4,775,000
Depreciation, amortization and accretion	468,000	(6,181,000)
Provision for loan losses	7,184,000	6,931,000
Gain on mortgage loans sold, net	(4,878,000)	(3,744,000)
Investement losses (gains) on sales, net	(1,960,000)	30,000
Stock-based compensation expense	4,913,000	4,448,000
Deferred tax expense	8,702,000	8,513,000
Gains on dispositions of other real estate and other investments	(50,000)	(481,000)
Income from equity method investment	(13,290,000)	(9,360,000)
Dividends received from equity method investment	12,666,000	4,324,000
Excess tax benefit from stock compensation	(769,000)	(2,681,000)
Gain on commercial loans sold, net	(611,000)	(936,000)
Commercial loans held for sale:
Loans originated	(80,117,000)	(80,193,000)
Loans sold	82,225,000	87,960,000
Consumer loans held for sale:
Loans originated	(243,870,000)	(247,025,000)
Loans sold	229,286,000	254,266,000
Increase in other assets	(6,517,000)	(9,302,000)
Increase (decrease) in other liabilities	59,720,000	(13,901,000)
Net cash provided by operating activities	155,291,000	80,893,000
Activities in securities available-for-sale:
Purchases	(312,605,000)	(590,328,000)
Sales	126,579,000	14,454,000
Maturities, prepayments and calls	72,813,000	81,737,000
Activities in securities held-to-maturity:
Maturities, prepayments and calls	15,000	0
Increase in loans, net	(462,940,000)	(683,710,000)
Purchases of software, premises and equipment	(2,110,000)	(8,806,000)
Proceeds from sales of software, premises and equipment	53,000	164,000
Proceeds from sale of other real estate	840,000	4,663,000
Purchase of bank owned life insurance policies	(60,000,000)	0
Increase in other investments	(12,582,000)	(836,000)
Net cash used in investing activities	(649,937,000)	(1,182,662,000)
Financing activities:
Net (decrease) increase in deposits	(368,466,000)	52,039,000
Net decrease in securities sold under agreements to repurchase	(4,043,000)	(3,398,000)
Advances from Federal Home Loan Bank:
Issuances	1,147,500,000	762,000,000
Payments/maturities	(470,014,000)	(105,014,000)
Decrease in other borrowings, net	(520,000)	(30,000)
Principal payments of finance lease obligation	(55,000)	(39,000)
Exercise of common stock options, net of repurchase of restricted shares	(3,357,000)	(3,649,000)
Payments for Repurchase of Common Stock	(30,049,000)	0
Common stock dividends paid	(12,545,000)	(10,974,000)
Net cash provided by financing activities	258,451,000	690,935,000
Net decrease in cash, cash equivalents, and restricted cash	(236,195,000)	(410,834,000)
Cash, cash equivalents, and restricted cash, beginning of period	721,692,000	779,597,000
Cash, cash equivalents, and restricted cash, end of period	$ 485,497,000	$ 368,763,000